A proposition stated without justification (by evidence or logical reasoning) that begins an argument. (Actually, the premise need not be stated explicitly, and need not come first in an argument, but it is always assumed to be true without further justification. Premises may be questioned, in which case they would need to be justified — but then they would no longer be the premises of the original argument.)

inference

A proposition that is derived from one or more premises through well defined logical rules. (The overall process of reasoning from premises to conclusions may also be known as inference.)

conclusion

A proposition that is the endpoint, or final goal, of a logical argument.